Abstract

We report on the electrical characteristics of HfO2 and HfO2/Al2O3 gate dielectrics deposited on n-In0.53Ga0.47As by atomic layer deposition, after in-situ hydrogen or nitrogen plasmasurface cleaning procedures, respectively. It is shown that alternating cycles of nitrogen plasma and trimethylaluminum prior to growth allow for highly scaled dielectrics with equivalent oxide thicknesses down to 0.6 nm and interface trap densities that are below 2.5 × 1012 cm−2 eV−1 near midgap. It is shown that the benefits of the nitrogen plasmasurface cleaning procedure are independent of the specific dielectric.

Received 14 November 2012Accepted 26 December 2012Published online 15 January 2013

Acknowledgments:

V.C. thanks Adam Kajdos for help with the AFM images. The authors gratefully acknowledge support for this work by the Semiconductor Research Corporation through the Nonclassical CMOS Research Center (Task ID 1437.008). J.S. was supported by NSF (award number ECCS-1125017). A portion of this work was performed in UCSB's nanofabrication facility, which is part of the NSF-funded NNIN network.